CPM therapy is used to aid in recovery following joint trauma and has been found to have beneficial results in the rehabilitation of injured joints and/or limbs. Passive motion can also be used for treatment of other bone and muscular disorders, such as arthritis.
The shoulder is formed where the clavicle, scapula and humerus join laterally. The joint formed is a ball and-socket type articulation between the proximal humerus and the glenoid cavity of the scapula. The socket is shallow, and the joint capsule is loose-fitting. As a result of this construction, the joint permits a wide range of motion but the joint is subject to poor stability and strength.
The shoulder is capable of three types of motion: abduction and adduction (up and down), simple back and forth (anterior/posterior), and rotation. Abduction and adduction is movement of the arm away from and toward the median axis, or long axis, in the median plane of the body, defined by the front or back of the body in a straight position. Back and forth motion means moving the arm forward and upward or backward and upward to increase the angle between the arm and the median plane of the body. Rotation is turning the arm about its long axis as if on a pivot.
Following shoulder injury, it is desirable to recover range of motion in the shoulder joint. It also would be desirable for a person recovering from a shoulder injury to have access to a CPM device that could be used in any location, such as, for example, a home or office. In view of the preceding, there is a need for a CPM device that can induce motion in a shoulder to aid in recovery and that can be relatively lightweight and/or portable for ease of use in any setting.